Gas turbine plant



June2 8, 1949. I, K. HUNG 2,474,582 4 GAS TURBINE PLANT Filed June 26, 1944 0/ 62 0 3 d4 d5 d6 03 rotation type of compressor.

Patented June 28, 1949 GAS TURBINE PLANT Ingvar Karl Einar-Jung, Langedrag, near Goteborg, Sweden Application June 26, 1944, Serial No. 542,141

In Sweden July 10, 1943 3 Claims. (Cl. 6041) 1 This invention relates to gas turbine plants. In the steam turbine art it has been well-known for many years past how to obtain high relative speeds and thus good eificiencies and alsohow to utilize compact turbine aggregates by the use of double rotation blading. Also in the gas turbine art proposals have been made in order to obtain used in this connection. The inventor has ascertained that by applying the double rotation system to the blades of the compressors forming part of gas turbine plants, essential advantages may be gained not only in respect of the compressors themselves but also as far as the plant as a whole is concerned. As to the compressors thecharacteristic feature of the double rotation system, which resides in high relative speeds at low peripheral velocities, aids in the obtainment of a reduced number of revolutions and, thus, the need of a. small number of rows of blades for a given pressure state as compared with a single Another property of the double rotation system, namely the substantially axial or radial fiow of the fluid to be compressed, leads to the advantage of reduced outlet and guide blade losses and to an improved distribution of pressure in radial direction as well.

All the advantages of the double rotation system, however, cannot be fully utilized owing to th sudden fall of the efliciency taking place in corhpressors having blades of aeroplane profiles, when the relative speed reaches values in the neighbourhood of the speed of sound. In'case of gas turbine plants where the highest compressor efliciency possible is an indispensable condition in order to render the plant fit for competition, it has proved-advisable not to use higher relative speeds than about 80% of the speed of sound. that is to say, in respect of air, speeds not higher than about 250 m./sec.

When applied to gas turbine plants comprising two independent or substantially independent gas turbines, the invention will prove especially profitable, since it permits a compact and simple arrangement and combination of parts.

In the accompanying drawing Fig. 1 illustrates trates a modified form of the plant of Fig. 1. Fig. 3 shows a characteristic curve representing the power distribution. 7

With reference to Fig. 1, the numeral l designates a compressor provided with a double rotation blading, the blades of which are, preferably, of aeroplane profile. The blading may be built so as to be fit for axial flow of the fluid. Numeral 2 designates an axial flow high pressure turbine the shaft of which is coupled to one shaft of the compressor, and 3 is likewise an axial flow low pressure turbine the shaft of which is coupled to the other shaft of the compressor. 4 is a heat chamber in which heat is supplied to the fluid as discharged from the compressor and delivered to the high pressure turbine, as for instance, air, either directly by the combustion of oil or the like or indirectly by the exchange of heat with a hotter fluid. Inserted in the connecting conduit between the high pressure'turbine and the low pressure turbine is a similar heater or heat exchanger 6. Inserted in the outlet conduit 1 of the low pressure turbine is a regener'ator 8 where a more or less great percentage of the heat contained inthe exhaust gases as escaping from the low pressure'turbine may be utilized to pre-heat the air escaping from the compressor before entering the heat chamber 4.

While in the embodiment shown the high pressure turbine is assumed to drive one shaft of the compressor only, the low pressure turbine is adapted to drive not only the other shaft of the compressor but also a dynamo 9, a machine tool or the like.

' Calculations have proved that the best emciency may be'obtained when about V3 of the total output is delivered by the high pressure turbine and about is delivered by the low pressure turbine, as will appear from the characteristic curve shown in Fig. 3 which represent the thermal emciency as a function of the relation between the high pressure turbine output and the total turbine output. It is thus seen that in this case the high pressure turbine transmits approximately half the compressor output, while the low pressure turbine transmits the other half of the compressor output together with the useful percentage of the exhaust gases as discharged from the low pressure turbine is cooled after leaving the regenerator 8 in order then to be introduced into the compressor, if desired, mixed an embodiment of such a plant. Fig. 2 illus-. with air.

The need of two oppositely rotating compressor shafts may be satisfled in a simple and practical way by the arrangement above. described. As the two bladings of the double rotation compressor may be driven at somewhat different speeds without any essential fall in eiiiciency, a certain speed regulation may be obtained in connection with the generator or the machine tool 9, while the speed of the other blading of the high pressure gas turbine and the compressor accommodates itself to the height of rise or the output r quired within certain limits.

In those cases in which the generator or the machine tool I requires a speed which within the larger portion of the rangeof load is independent of the load, or a constant speed or a speed depending on the load in a certain degree, the low pressure turbine may, preferably, be sub-divided into two parallel units 3 I, as shown in Fig. 2. The turbine unit I is coupled to one blading ot the compressor, whereas the other entirely independent turbine unit 3' acts to drive the generator or the machine tool a. For the rest, this embodiment corresponds to that above described.

What I claim is:

1. A gas turbine plant comprising, a high-pressure gas turbine, a low-pressure gas turbine, a series connection therebetween for feeding the eiiluent of the high-pressure turbine to the lowpressure turbine, a heat chamber in said connection, a compressor having two rotors arranged for opposite rotation, means for coupling each rotor to a separate one of said turbines so as to be driven thereby, a load connected to the low pressure turbine so as to be driven thereby, a connection for delivering the compressed fluid to the high-pressure turbine, a heat chamber in said eiiluent of the high-pressure turbine to said parallel connection, a compressor having two rotors arranged for opposite rotation, one rotor being coupled to the high-pressure turbine so as to be driven thereby and the other rotor being coupled to one of the low-pressure turbines so as to be driven thereby, a load connected to the other low-pressure turbine so as to be driven thereby, a connection for feeding the compressed fluid to the high-pressure turbine, a heat chamber in said connection, and means to recover heat from the efluent of the low-pressure turbines to the compressed fluid before entering said last-mentioned heat chamber.

3. A gas turbine plant comprising. acompressor 7 having two rotors arranged for opposite rotation, a load, two locally spaced gas turbines, namely, a high-pressure turbine coupled to one rotor of the compressor for driving same and a low-pressure turbine coupled to the other rotor of the compressor and to said load, means for passing the compressed eifluent of the compressor to the high-pressure turbine, andmeans for passing the eiliuent of the-high-pressure turbine to the lowpressure turbine, the low-pressure turbine being,

' soproportioned with relation to the high-presconnection, and means for recovering heat from the exhaust gases of the low pressure turbine and delivering it to the compressed fluid before entering said last-mentioned heat chamber.

2. A gas turbine plant comprising, a high-pressure gas turbine, two low-pressure gas turbines, a parallel feeding connection therebetween, means including a heat chamber for passin the sure turbine as to deliver about twice the power delivered by the high-pressure turbine for allowing it to drive both one rotor of the compressor and the load.

INGVAR KARL'EINAR JUNG.

REFERENCES -cr'rnn The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,316,234 Heinze Sept. 16, 1919 2,095,991 Lyshoim Oct. 19, 1937 2,280,765 Anxionnaa Apr. 21, 1942 2,338,232 Doran Dee-I, 1943 2,365,551 Hermitte Dec. 19, 1944 

